An AlGaInP red light semiconductor laser with a V-type mode extension layer and its preparation method

Abstract

The present invention relates to an AlGaInP red light semiconductor laser with a V-type mode expansion layer and a preparation method thereof. The laser comprises, from bottom to top, a GaAs substrate, a GaAs buffer layer, a GaAs 0.5 In 0.5 P lower transition layer, Al 0.5 In 0.5 P first lower limiting layer, V-type composition change (Al a1 Ga 1‑a1 ) b1 In 1‑b1 P-mode extension layer, Al 0.5 In 0.5 P second lower confinement layer, (Al x1 Ga 1‑x1 ) y1 In 1‑ y1 P lower waveguide layer, Ga 1‑x2 In x2 P first quantum well, (Al x3 Ga 1‑x3 ) y2 In 1‑y2 P barrier layer, Ga 1‑x4 In x4 P second quantum well, (Al x5 Ga 1‑x5 ) y3 In 1‑y3 P upper waveguide layer, Al 0.5 In 0.5 P first upper confinement layer, Ga 1‑x6 In x6 P corrosion stop layer, Al 0.5 In 0.5 P second upper confinement layer, Ga 0.5 In 0.5 The present invention is achieved by forming a transition layer on the P and a GaAs cap layer. 0.5 In 0.5 P first lower confinement layer and Al 0.5 In 0.5 P second lower confinement layer inserted between the composition V-type change (Al a1 Ga 1‑a1 ) b1 In 1‑b1 The P-mode extension layer eliminates the optical field offset caused by the refractive index change of the corrosion stop layer, improves the overlap between the optical field and the quantum well, and reduces the threshold current.

Description

Technical Field

[0001] The invention relates to an AlGaInP red light semiconductor laser with a V-shaped mode expansion layer and a preparation method thereof, belonging to the technical field of optoelectronics. Background Art

[0002] AlGaInP red light semiconductor lasers are characterized by small size, light weight, low power consumption, direct modulation, high efficiency and reliability. They have broad application prospects in short-range all-optical network applications in plastic optical fiber transmission and in medical beauty, laser display and industrial measurement.

[0003] The coupling efficiency of single-mode lasers in optical fiber transmission is much greater than that of multi-mode lasers. The ridge waveguide depth is a key parameter for optimizing the performance of ridge waveguide devices. (Al)GaInP is used as a corrosion barrier layer. The different wet etching properties of materials with different Al components can be used to improve the consistency of the corrosion depth. However, the corrosion barrier layer forms a longitudinal refractive index step difference, which easily leads to light field deviation. At the same time, the literature IEEE journal of quantum electronics, Vol 36(6), 2000, Pg: 742-750 points out that due to the small band gap difference of the conduction band of AlGaInP material, electron overflow will lead to luminescence in the GaInP material, which will also cause light field deviation.

[0004] The literature Semiconductor Science and Technology, Vol 29, 2014, 045010:1–6 uses asymmetric components and waveguide layer thickness to achieve light field offset, which can reduce thermal resistance and carrier absorption loss. However, it also points out that light field offset will cause the light field peak to not coincide with the quantum well, resulting in a decrease in the light confinement factor and an increase in the threshold current.

[0005] The IEEE Journal of Quantum Electronics, Vol. 41(9), 2005, Pg: 1124-1129, points out that the use of a V-shaped composition-variation mode extension layer can reduce the vertical divergence angle and increase the kink power. Furthermore, compared with a step-shaped composition-mutation mode extension layer, the influence of Al composition fluctuations on the coincidence between the light field and the quantum well is smaller. However, the full article focuses on the light field offset caused by slight changes in the refractive index of the confinement layer after different doping types, and does not involve the application of (Al)GaInP etching stop layers. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention provides an AlGaInP red light semiconductor laser with a V-type mode expansion layer and a preparation method thereof.

[0007] The technical solutions of the present invention are as follows:

[0008] An AlGaInP red light semiconductor laser with a V-type mode extension layer, which comprises, from bottom to top, a GaAs substrate, a GaAs buffer layer, a GaAs 0.5 In 0.5 P lower transition layer, Al 0.5 In 0.5 P first lower limiting layer, V-type composition change (Al a1 Ga 1-a1 ) b1 In 1-b1 P-mode extension layer, Al 0.5 In 0.5 P second lower confinement layer, (Al x1 Ga 1-x1 ) y1 In 1-y1 P lower waveguide layer, Ga 1-x2 In x2 P first quantum well, (Al x3 Ga 1-x3 ) y2 In 1-y2 P barrier layer, Ga 1-x4 In x4 P second quantum well, (Al x5 Ga 1-x5 ) y3 In 1-y3 P upper waveguide layer, Al 0.5 In 0.5 P first upper confinement layer, Ga 1-x6 In x6 P corrosion stop layer, Al 0.5 In 0.5 P second upper confinement layer, Ga 0.5 In 0.5 P upper transition layer and GaAs cap layer;

[0009] The a1 component changes from large to small and then from small to large, forming a V-shaped compositional change. By inserting a mode expansion layer, the light field is shifted toward the N confinement layer, improving the overlap between the light field and the quantum well and lowering the threshold current. This V-shaped compositional change reduces the impact of Al composition fluctuations on the light field shift and improves stability.

[0010] Preferably according to the present invention, the substrate is a GaAs substrate.

[0011] According to the preferred embodiment of the present invention, the GaAs buffer layer is a GaAs material doped with silicon atoms, the doping source is Si2H6, the thickness is 0.1-0.3 μm, and the doping concentration is 2×10 18 -5×10 18atoms / cm 3 Preferably, the thickness of the buffer layer is 0.2 μm and the doping concentration of silicon atoms is 2×10 18 atoms / cm 3 .

[0012] According to the present invention, preferably, the Ga 0.5 In 0.5 The P lower transition layer is doped with silicon atoms, the doping source is Si2H6, the thickness is 0.1-0.3μm, and the doping concentration is 2×10 18 -5×10 18 atoms / cm 3 Preferably, the Ga 0.5 In 0.5 The thickness of the P lower transition layer is 0.2 μm; the doping concentration is 4×10 18 atoms / cm 3 .

[0013] According to the present invention, preferably, the Al 0.5 In 0.5 The first lower confinement layer is n-type Al 0.5 In 0.5 The first lower limiting layer P is doped with silicon atoms, the doping source is Si2H6, the thickness is 0.5-1μm, and the doping concentration is 7×10 17 -2×10 18 atoms / cm 3 Preferably, the Al 0.5 In 0.5 The thickness of the first lower confinement layer is 0.9 μm; the doping concentration is 1×10 18 atoms / cm 3 .

[0014] According to the preferred embodiment of the present invention, the composition of the V-type change (Al a1 Ga 1-a1 ) b1 In 1-b1 The P-mode extension layer is doped with silicon atoms, the doping source is Si2H6, the thickness is 0.01-0.03μm, and the doping concentration is 7×10 17 -2×10 18 atoms / cm 3 , wherein a1 in the mode expansion layer of half thickness changes gradually from 0.95 to 0.55, and in the mode expansion layer of the other half thickness changes gradually back to 0.95 from 0.55, 0.4≤b1≤0.6. Preferably, the V-shaped change of the composition (Al a1 Ga 1-a1 ) b1 In 1-b1The thickness of the P-mode extension layer is 0.02 μm and the doping concentration is 1×10 18 atoms / cm 3 , where a1 in the 0.01 μm thickness mode extension layer gradually changes from 0.95 to 0.7, and in the other 0.01 μm thickness mode extension layer, a1 gradually changes back from 0.7 to 0.95, and b1 = 0.5.

[0015] According to the present invention, preferably, the Al 0.5 In 0.5 The second lower confinement layer of P is n-type Al 0.5 In 0.5 The second lower confinement layer is doped with silicon atoms, the doping source is Si2H6, the thickness is 0.05-0.2μm, and the doping concentration is 7×10 17 -2×10 18 atoms / cm 3 Preferably, the Al 0.5 In 0.5 The thickness of the second lower confinement layer is 0.1 μm; the doping concentration is 1×10 18 atoms / cm 3 .

[0016] According to the present invention, preferably, the (Al x1 Ga 1-x1 ) y1 In 1-y1 The thickness of the waveguide layer under P is 0.05-0.15 μm, not intentionally doped, 0.45≤x1≤0.95, 0.4≤y1≤0.6; preferably, the (Al x1 Ga 1-x1 ) y1 In 1-y1 The thickness of the waveguide layer under P is 0.1 μm, x1 gradually changes from 0.95 to 0.5, and y1=0.5.

[0017] According to the present invention, preferably, the Ga 1-x2 In x2 The thickness of the P first quantum well is 4-7nm, unintentionally doped, 0.3≤x2≤0.5, and is under compressive strain. 1-x2 In x2 The thickness of the first quantum well P is 5 nm, and x2=0.4.

[0018] According to the present invention, preferably, the (Al x3 Ga 1-x3 ) y2 In 1-y2 The thickness of the P barrier layer is 5-15nm, not intentionally doped, 0.4≤x3≤0.7, 0.4≤y2≤0.6, and is subjected to tensile strain.x3 Ga 1-x3 ) y2 In 1-y2 The thickness of the P barrier layer is 6 nm, x3=0.65, y2=0.42.

[0019] According to the present invention, preferably, the Ga 1-x4 In x4 The thickness of the P second quantum well is 4-7nm, unintentionally doped, 0.3≤x4≤0.5, and is under compressive strain. 1-x4 In x4 The thickness of the second quantum well P is 5 nm, and x4=0.4.

[0020] According to the present invention, preferably, the (Al x5 Ga 1-x5 ) y3 In 1-y3 The waveguide layer on P is doped with magnesium atoms or zinc atoms. The doping source is Cp2Mg or DEZn. The doping form is half doping. The thickness is 0.05-0.15μm and the doping concentration is 3×10 17 -7×10 17 atoms / cm 3 , x5 changes gradually from 0.5 to 0.95, 0.4≤y3≤0.6. Preferably, the (Al x5 Ga 1-x5 ) y3 In 1-y3 The thickness of the P upper waveguide layer is 0.1 μm, and the 0.05 μm upper waveguide layer away from the quantum well is doped with magnesium atoms. The doping source is Cp2Mg, and the doping concentration is 4×10 17 atoms / cm 3 , x5 gradually changes from 0.5 to 0.95, y3=0.5.

[0021] According to the present invention, preferably, the Al 0.5 In 0.5 The first upper confinement layer is p-type Al 0.5 In 0.5 The first upper confinement layer P is doped with magnesium atoms or zinc atoms, the doping source is Cp2Mg or DEZn, the thickness is 0.1-0.3μm, and the doping concentration is 7×10 17 -1.5×10 18 atoms / cm 3 Preferably, the Al 0.5 In 0.5 The thickness of the first upper confinement layer of P is 0.15 μm, the doping source is Cp2Mg, and the doping concentration is 1×10 18 atoms / cm 3 .

[0022] According to the present invention, preferably, the Ga 1-x6 In x6 The P corrosion stop layer is doped with magnesium atoms or zinc atoms. The doping source is Cp2Mg or DEZn. The thickness is 8-20nm and the doping concentration is 1.2×10 18 -3×10 18 atoms / cm 3 , 0.4≤x6≤0.5. Preferably, the Ga 1-x6 In x6 The thickness of the P corrosion stop layer is 10 nm, the doping source is Cp2Mg, and the doping concentration is 1.5×10 18 atoms / cm 3 , x6=0.47.

[0023] According to the present invention, preferably, the Al 0.5 In 0.5 The second upper confinement layer is p-type Al 0.5 In 0.5 The second upper confinement layer is doped with magnesium atoms or zinc atoms. The doping source is Cp2Mg or DEZn. The thickness is 0.5-1.2μm and the doping concentration is 7×10 17 -1.5×10 18 atoms / cm 3 Preferably, the Al 0.5 In 0.5 The thickness of the second upper confinement layer of P is 0.7 μm, the doping source is Cp2Mg, and the doping concentration is 1×10 18 atoms / cm 3 .

[0024] According to the present invention, preferably, the Ga 0.5 In 0.5 The transition layer on P is doped with magnesium atoms or zinc atoms. The doping source is Cp2Mg or DEZn. The thickness is 20-40nm and the doping concentration is 1.2×10 18 -3×10 18 atoms / cm 3 Preferably, the Ga 0.5 In 0.5 The thickness of the transition layer on P is 24 nm, the doping source is Cp2Mg, and the doping concentration is 2×10 18 atoms / cm 3 .

[0025] According to the preferred embodiment of the present invention, the GaAs cap layer is a GaAs material doped with carbon atoms, the doping source is CBr4 or DEZn, the thickness is 0.1-0.5 μm, and the doping concentration is 4×10 19 -1×10 20atoms / cm 3 Preferably, the thickness of the GaAs cap layer is 0.2 μm, the doping source is CBr4, and the doping concentration is 7×10 19 atoms / cm 3 .

[0026] The method for preparing the AlGaInP red light semiconductor laser with a V-type mode extension layer comprises the following steps:

[0027] The substrate is subjected to surface heat treatment in the MOCVD growth chamber, and then the GaAs substrate, GaAs buffer layer, GaAs and GaAs are grown epitaxially from bottom to top. 0.5 In 0.5 P lower transition layer, Al 0.5 In 0.5 P first lower limiting layer, V-type composition change (Al a1 Ga 1-a1 ) b1 In 1-b1 P-mode extension layer, Al 0.5 In 0.5 P second lower confinement layer, (Al x1 Ga 1-x1 ) y1 In 1-y1 P lower waveguide layer, Ga 1-x2 In x2 P first quantum well, (Al x3 Ga 1-x3 ) y2 In 1-y2 P barrier layer, Ga 1-x4 In x4 P second quantum well, (Al x5 Ga 1-x5 ) y3 In 1-y3 P upper waveguide layer, Al 0.5 In 0.5 P first upper confinement layer, Ga 1-x6 In x6 P corrosion stop layer, Al 0.5 In 0.5 P second upper confinement layer, Ga 0.5 In 0.5 P upper transition layer and GaAs cap layer.

[0028] Preferably, according to the present invention, the AlGaInP red light semiconductor laser with a V-type mode extension layer comprises the following steps:

[0029] (1) placing a GaAs substrate in a growth chamber of an MOCVD device, heating the substrate to 710-730° C. in an H2 environment and baking the substrate for 20-40 minutes, then introducing AsH3 and baking the substrate for 20-40 minutes to obtain a heat-treated GaAs substrate; performing a high-temperature heat treatment on the GaAs substrate to remove water and oxygen from the substrate surface, and preparing for step (2);

[0030] (2) Lowering the temperature to 670-690°C at a cooling rate of no more than 30°C / min, introducing TMGa and AsH3, and growing a GaAs buffer layer on the GaAs substrate; the purpose is to prevent defects from propagating from the substrate into the confinement layer, provide a fresh growth interface, and improve the quality of material growth;

[0031] (3) Maintaining the temperature at 670-690°C, introducing TMGa, PH3 and AsH3, and stopping the introduction of AsH3 and TMGa during the growth process on the GaAs buffer layer to achieve a growth pause. The pause time is 3s to 30s, and the As atoms in the reaction chamber are depleted;

[0032] (4) Maintaining the temperature at 670-690°C, continue to introduce TMGa, TMIn and PH3 to grow GaAs on the GaAs buffer layer. 0.5 In 0.5 P lower transition layer; its purpose is to reduce the band gap mutation and increase the electron migration rate;

[0033] (5) Raise the temperature to 690-710℃ at a rate not higher than 60℃ / min, introduce TMAl, TMIn and PH3, and 0.5 In 0.5 Al growth on the transition layer below P 0.5 In 0.5 P first lower limiting layer;

[0034] (6) Maintain the temperature at 690-710℃, introduce TMAl, TMGa, TMIn and PH3, and 0.5 In 0.5 The growth composition of the first lower confinement layer is V-shaped (Al a1 Ga 1-a1 ) b1 In 1-b1 In the P-mode extension layer, by changing the flow rates of TMAl and TMGa while keeping the flow rate of TMIn constant, a V-shaped change of the Al composition from large to small and then from small to large is achieved;

[0035] (7) Maintain the temperature at 690-710℃, continue to introduce TMAl, TMIn and PH3, and in the V-type change of the composition (Al a1 Ga 1-a1 ) b1 In 1-b1Al growth on the P-mode extension layer 0.5 In 0.5 P second lower limiting layer;

[0036] (8) Lower the temperature to 640-660℃, continue to introduce TMAl, TMIn, TMGa and PH3, 0.5 In 0.5 P second lower confinement layer grows (Al x1 Ga 1-x1 ) y1 In 1-y1 The waveguide layer under P; by changing the flow rate of TMAl and TMGa, while keeping the flow rate of TMIn unchanged, the Al composition is gradually changed. The gradual change of the band gap helps to improve the carrier injection efficiency and enhance the photoelectric conversion efficiency;

[0037] (9) Maintain the temperature at 640-660℃, continue to introduce TMIn, TMGa and PH3, and x1 Ga 1-x1 ) y1 In 1-y1 Ga is grown on the waveguide layer below P 1-x2 In x2 P first quantum well;

[0038] (10) Keep the temperature at 640-660℃, continue to introduce TMAl, TMIn, TMGa and PH3, and 1-x2 In x2 P first quantum well (Al x3 Ga 1-x3 ) y2 In 1-y2 P barrier layer;

[0039] (11) Maintain the temperature at 640-660℃, continue to introduce TMIn, TMGa and PH3, x3 Ga 1-x3 ) y2 In 1-y2 Ga growth on the P barrier layer 1-x4 In x4 P second quantum well;

[0040] (12) Raise the temperature to 690-710℃, continue to introduce TMAl, TMIn, TMGa and PH3, and 1-x4 In x4 P second quantum well (Al x5 Ga 1-x5 ) y3 In 1-y3The waveguide layer on the P top layer; by changing the flow rate of TMAl and TMGa, while keeping the flow rate of TMIn unchanged, the Al composition is gradually changed. The gradual change of the band gap helps to improve the carrier injection efficiency and enhance the photoelectric conversion efficiency;

[0041] (13) Maintain the temperature at 690-710℃, continue to introduce TMAl, TMIn and PH3, x5 Ga 1-x5 ) y3 In 1-y3 P-type Al is grown on the P upper waveguide layer 0.5 In 0.5 P first upper confinement layer;

[0042] (14) Maintain the temperature at 690-710℃, continue to introduce TMGa, TMIn and PH3, and 0.5 In 0.5 P-type GaN is grown on the first upper confinement layer. 1-x6 In x6 P corrosion stop layer;

[0043] (15) Maintain the temperature at 690-710℃, continue to introduce TMAl, TMIn and PH3, and 1-x6 In x6 Al growth on P etch stop layer 0.5 In 0.5 P second upper confinement layer;

[0044] (16) Lower the temperature to 670-690℃, introduce TMIn, TMGa and PH3, and 0.5 In 0.5 Ga is grown on the second upper confinement layer of P 0.5 In 0.5 P upper transition layer;

[0045] (17) The temperature was lowered to 530-550 ° C, and the cooling rate did not exceed 40 ° C / min, and TMGa and AsH3 were continued to be introduced. 0.5 In 0.5 A GaAs cap layer is grown on the P upper transition layer.

[0046] Preferably, according to the present invention, in step (1), the temperature is raised to 720° C. in a H 2 environment and baked for 30 minutes, and then AsH 3 is introduced and baked for 30 minutes.

[0047] Preferably according to the present invention, in step (2), the reaction temperature is 680°C.

[0048] Preferably according to the present invention, in step (3), the reaction temperature is 680°C.

[0049] Preferably according to the present invention, in step (4), the reaction temperature is 680°C.

[0050] Preferably according to the present invention, in step (5), the reaction temperature is 700°C.

[0051] Preferably according to the present invention, in step (6), the reaction temperature is 700°C.

[0052] Preferably according to the present invention, in step (7), the reaction temperature is 700°C.

[0053] Preferably according to the present invention, in step (8), the reaction temperature is 650°C.

[0054] Preferably according to the present invention, in step (9), the reaction temperature is 650°C.

[0055] Preferably according to the present invention, in step (10), the reaction temperature is 650°C.

[0056] Preferably according to the present invention, in step (11), the reaction temperature is 650°C.

[0057] According to the preferred embodiment of the present invention, in step (12), the reaction temperature is 700°C.

[0058] According to the preferred embodiment of the present invention, in step (13), the reaction temperature is 700°C.

[0059] Preferably according to the present invention, in step (14), the reaction temperature is 700°C.

[0060] Preferably according to the present invention, in step (15), the reaction temperature is 700°C.

[0061] Preferably according to the present invention, in step (16), the reaction temperature is 680°C.

[0062] According to the preferred embodiment of the present invention, in step (17), the reaction temperature is 540°C.

[0063] The MOCVD equipment, ICP etching equipment, etc. used in the method of the present invention are all existing technologies.

[0064] In the present invention, TMGa, TMIn, TMAl, PH3, AsH3, etc. are all MOCVD epitaxial growth raw materials, Si2H6, Cp2Mg, CBr4, DEZn, etc. are all epitaxial growth doping sources, and except for the cap layer GaAs, the quantum well upper layer doping source is the same doping source.

[0065] The beneficial effects of the present invention are as follows:

[0066] 1. The present invention is achieved by 0.5 In 0.5P first lower confinement layer and Al 0.5 In 0.5 P is inserted between the second lower confinement layer (Al a1 Ga 1-a1 ) b1 In 1-b1 The P-mode extension layer eliminates the optical field offset caused by the refractive index change of the corrosion stop layer, improves the overlap between the optical field and the quantum well, and reduces the threshold current.

[0067] 2. The AlGaInP red light semiconductor laser provided by the present invention (Al a1 Ga 1-a1 ) b1 In 1-b1 The V-shaped composition change of the P-mode extension layer reduces the influence of Al composition fluctuation on the optical field deviation and improves stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 Schematic diagram comparing the structure of the laser of the present invention (a) and a conventional AlGaInP red semiconductor laser (b);

[0069] In the figure: 1 is GaAs substrate; 2, GaAs buffer layer; 3, Ga 0.5 In 0.5 P lower transition layer; 4 is Al 0.5 In 0.5 P first lower limiting layer; 5, composition V-type change (Al a1 Ga 1-a1 ) b1 In 1-b1 P-mode extension layer; 6. Al 0.5 In 0.5 P second lower confinement layer; 7, (Al x1 Ga 1-x1 ) y1 In 1-y1 P lower waveguide layer; 8, Ga 1-x2 In x2 P first quantum well; 9, (Al x3 Ga 1-x3 ) y2 In 1-y2 P barrier layer; 10, Ga 1-x4 In x4 P second quantum well; 11, (Al x5 Ga 1-x5 ) y3 In 1-y3 P upper waveguide layer; 12, Al 0.5 In 0.5 P first upper confinement layer; 13, Ga 1-x8 In x8P corrosion stop layer; 14, Al 0.5 In 0.5 P second upper confinement layer; 15, Ga 0.5 In 0.5 P upper transition layer; 16, GaAs cap layer;

[0070] Figure 2 Schematic diagrams of the designs of the laser of the present invention (a) and a conventional AlGaInP red light semiconductor laser (b).

[0071] Figure 3 3. The figure compares the PIV test curves of the laser (a) of the present invention and the conventional AlGaInP red semiconductor laser (b) after coating with a cavity length of 300 μm and a strip width of 5 μm, wherein the horizontal axis is the operating current and the vertical axis on the left is the output power. DETAILED DESCRIPTION

[0072] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0073] Unless otherwise specified, the raw materials used in the examples are conventional raw materials and are commercially available; the methods used are all existing methods unless otherwise specified.

[0074] Example 1

[0075] A method for preparing an AlGaInP red light semiconductor laser with a V-type mode extension layer comprises the following steps:

[0076] (1) placing a GaAs substrate in a growth chamber of an MOCVD device, heating it to 720° C. in an H2 environment and baking it for 30 minutes, then introducing AsH3 and baking it for 30 minutes to obtain a heat-treated GaAs substrate; performing a high-temperature heat treatment on the GaAs substrate to remove water and oxygen from the substrate surface, and preparing for step (2);

[0077] (2) The temperature was lowered to 680°C at a cooling rate of no more than 30°C / min, and TMGa and AsH3 were introduced to grow a GaAs buffer layer with a thickness of 0.2 μm on the GaAs substrate; the doping source was Si2H6 with a doping concentration of 2×10 18 atoms / cm 3 ;

[0078] (3) Maintaining the temperature at 680°C, introducing TMGa, AsH3, and PH3, and stopping the introduction of AsH3 and TMGa during the growth process on the GaAs buffer layer to achieve a growth pause for 15 seconds, depleting the As atoms in the reaction chamber;

[0079] (4) Maintaining the temperature at 680°C, continue to introduce TMGa, TMIn and PH3 to grow GaAs with a thickness of 0.2 μm on the GaAs buffer layer.0.5 In 0.5 P lower transition layer; the doping source is Si2H6, and the doping concentration is 4×10 18 atoms / cm 3 ;

[0080] (5) Raise the temperature to 700℃ at a rate not higher than 60℃ / min, introduce TMAl, TMIn and PH3, and 0.5 In 0.5 The n-type Al with a thickness of 0.9 μm is grown on the P lower transition layer. 0.5 In 0.5 P first lower confinement layer; the doping source is Si2H6, and the doping concentration is 1×10 18 atoms / cm 3 ;

[0081] (6) Keep the temperature at 700℃, introduce TMAl, TMIn, TMGa and PH3, and 0.5 In 0.5 The first lower confinement layer of P is grown with a thickness of 0.02 μm and a V-type composition change (Al a1 Ga 1-a1 ) b1 In 1-b1 P-mode extension layer, doping source is Si2H6, doping concentration is 1×10 18 atoms / cm 3 , where a1 in the 0.01 μm thick mode expansion layer gradually changes from 0.95 to 0.7, and in another 0.01 μm thick mode expansion layer, a1 gradually changes from 0.7 back to 0.95, and b1 = 0.5;

[0082] (7) Keep the temperature at 700℃, continue to introduce TMAl, TMIn and PH3, and in the V-type change of composition (Al a1 Ga 1-a1 ) b1 In 1-b1 A 0.1 μm thick Al2O3 layer is grown on the P-mode extension layer. 0.5 In 0.5 The second lower confinement layer is P, the doping source is Si2H6, and the doping concentration is 1×10 18 atoms / cm 3 ;

[0083] (8) Lower the temperature to 650℃ and continue to introduce TMAl, TMIn, TMGa and PH3. 0.5 In 0.5 A 0.1 μm thick (Al x1 Ga 1-x1 ) y1 In1-y1 The waveguide layer below P is not intentionally doped, with x1 gradually changing from 0.95 to 0.5 and y1 = 0.5. By changing the flow rates of TMAl and TMGa, while keeping the flow rate of TMIn unchanged, the Al composition is gradually changed. The gradual change of the band gap helps to improve the carrier injection efficiency and enhance the photoelectric conversion efficiency.

[0084] (9) Maintaining the temperature at 650°C, continue to introduce TMIn, TMGa and PH3. x1 Ga 1-x1 ) y1 In 1-y1 A 5nm thick GaN layer is grown on the P waveguide layer. 1-x2 In x2 P first quantum well, unintentionally doped, x2 = 0.4, compressive strain;

[0085] (10) Keep the temperature at 650℃, continue to introduce TMAl, TMIn, TMGa and PH3, and 1-x2 In x2 A 6 nm thick (Al2O3) is grown on the first quantum well of P x3 Ga 1-x3 ) y2 In 1-y2 P barrier layer, unintentionally doped, x3 = 0.65, y2 = 0.42, under tensile strain;

[0086] (11) Keep the temperature at 650℃, continue to introduce TMIn, TMGa and PH3, and x3 Ga 1-x3 ) y2 In 1-y2 A 5nm thick GaN layer is grown on the P barrier layer. 1-x4 In x4 P second quantum well, unintentionally doped, x4 = 0.4;

[0087] (12) Raise the temperature to 700℃ and continue to introduce TMAl, TMIn, TMGa and PH3. 1-x4 In x4 A 0.1 μm thick (Al x5 Ga 1-x5 ) y3 In 1-y3 The upper waveguide layer of P is doped in half, where the upper waveguide layer 0.05 μm away from the quantum well is doped with magnesium atoms. The doping source is Cp2Mg, and the doping concentration is 4×10 17 atoms / cm 3, x5 gradually changes from 0.5 to 0.95, y3 = 0.5; by changing the flow rate of TMAl and TMGa, while keeping the flow rate of TMIn unchanged, the Al composition is gradually changed, and the band gap gradually changes, which helps to improve the carrier injection efficiency and the photoelectric conversion efficiency;

[0088] (13) Keep the temperature at 700℃, continue to introduce TMAl, TMIn and PH3, x5 Ga 1-x5 ) y3 In 1-y3 A P-type Al with a thickness of 0.15 μm is grown on the P upper waveguide layer. 0.5 In 0.5 The first upper confinement layer is P, the doping source is Cp2Mg, and the doping concentration is 1×10 18 atoms / cm 3 ;

[0089] (14) Maintain the temperature at 700℃, continue to introduce TMGa, TMIn and PH3, and 0.5 In 0.5 P-type Ga with a thickness of 10 nm is grown on the first upper confinement layer. 1-x6 In x6 P corrosion stop layer, the doping source is Cp2Mg, and the doping concentration is 1.5×10 18 atoms / cm 3 , x6=0.47;

[0090] (15) Keep the temperature at 700℃, continue to introduce TMAl, TMIn and PH3, and 1-x6 In x6 A 0.7 μm thick Al layer was grown on the P corrosion stop layer. 0.5 In 0.5 The second upper confinement layer is P, the doping source is Cp2Mg, and the doping concentration is 1×10 18 atoms / cm 3 ;

[0091] (16) Lower the temperature to 680℃, introduce TMIn, TMGa and PH3, and 0.5 In 0.5 GaN with a thickness of 24 nm is grown on the second upper confinement layer of P. 0.5 In 0.5 The transition layer on P is doped with Cp2Mg and the doping concentration is 2×10 18 atoms / cm 3 ;

[0092] (17) The temperature was lowered to 540 °C at a rate not exceeding 40 °C / min, and TMGa and AsH3 were continuously introduced. 0.5 In0.5 A GaAs cap layer with a thickness of 0.2 μm is grown on the P upper transition layer. The doping source is CBr4 with a doping concentration of 7×10 19 atoms / cm3.

[0093] The structure of the laser described in this embodiment 1 is as follows Figure 1 As shown in (a), a conventional AlGaInP red light semiconductor laser is Figure 1 As shown in (b), Figure 1 (a) and Figure 1 (b) By comparison, it can be seen that the present invention 0.5 In 0.5 P first lower confinement layer and Al 0.5 In 0.5 P is inserted between the second lower confinement layer (Al a1 Ga 1-a1 ) b1 In 1-b1 The P-mode extension layer eliminates the optical field offset caused by the refractive index change of the corrosion stop layer, improves the overlap between the optical field and the quantum well, and reduces the threshold current.

[0094] The schematic diagram of the laser design in Example 1 is as follows Figure 2 As shown in (a), a conventional AlGaInP red light semiconductor laser is Figure 2 As shown in (b), Figure 2 (a) and Figure 2 (b) By comparison, it can be seen that the conventional AlGaInP red light semiconductor laser is affected by the GaInP corrosion termination layer, the light field is offset, and there is a certain distance from the quantum well. The laser described in Example 1 inserts a V-shaped composition gradient layer in the lower confinement layer as a mode expansion layer, which improves the overlap between the actual light field and the quantum well.

[0095] Example 2

[0096] A method for preparing an AlGaInP red semiconductor laser with a V-type mode extension layer is as described in Example 1, except that:

[0097] In step (2), the thickness of the GaAs buffer layer is 0.1 μm, and the doping concentration of silicon atoms is 3×10 18 atoms / cm 3 .

[0098] In step (4), Ga 0.5 In 0.5 The thickness of the P lower transition layer is 0.1 μm and the doping concentration is 2×10 18 atoms / cm 3 .

[0099] In step (5), Al0.5 In 0.5 The thickness of the first lower confinement layer is 0.5 μm and the doping concentration is 7×10 17 atoms / cm 3 .

[0100] In step (6), the composition of the V-type change (Al a1 Ga 1-a1 ) b1 In 1-b1 The thickness of the P-mode extension layer is 0.01 μm and the doping concentration is 7×10 17 atoms / cm 3 , where a1 in the 0.005 μm thickness mode extension layer gradually changes from 0.95 to 0.45, and in the other 0.005 μm thickness mode extension layer, a1 gradually changes back from 0.45 to 0.95, and b1 = 0.4.

[0101] In step (7), Al 0.5 In 0.5 The thickness of the second lower confinement layer is 0.05 μm and the doping concentration is 7×10 17 atoms / cm 3 . .

[0102] In step (8), (Al x1 Ga 1-x1 ) y1 In 1-y1 The thickness of the waveguide layer under P is 0.05 μm, it is not intentionally doped, x1 gradually changes from 0.95 to 0.45, and y1 = 0.5.

[0103] In step (9), Ga 1-x2 In x2 The thickness of the P first quantum well is 4 nm, it is not intentionally doped, and x2=0.3.

[0104] In step (10), (Al x3 Ga 1-x3 ) y2 In 1-y2 The thickness of the P barrier layer is 5 nm, it is not intentionally doped, x3=0.4, y2=0.4.

[0105] In step (11), Ga 1-x4 In x4 The thickness of the P second quantum well is 4 nm, it is not intentionally doped, and x4=0.3.

[0106] In step (12), (Al x5 Ga 1-x5 ) y3 In 1-y3The thickness of the waveguide layer on P is 0.05 μm, of which 0.025 μm away from the quantum well is doped with zinc atoms. The doping source is DEZn, and the doping concentration is 3×10 17 atoms / cm 3 .

[0107] In step (13), Al 0.5 In 0.5 The thickness of the first upper confinement layer of P is 0.1 μm, the doping source is DEZn, and the doping concentration is 7×10 17 atoms / cm 3 .

[0108] In step (14), Ga 1-x6 In x6 The thickness of the P corrosion stop layer is 8 nm, the doping source is DEZn, and the doping concentration is 1.2×10 18 atoms / cm 3 , x6=0.4.

[0109] In step (15), Al 0.5 In 0.5 The thickness of the second upper confinement layer is 0.5 μm, the doping source is DEZn, and the doping concentration is 7×10 17 atoms / cm 3 .

[0110] In step (16), Ga 0.5 In 0.5 The thickness of the transition layer on P is 20 nm, the doping source is DEZn, and the doping concentration is 2×10 18 atoms / cm 3 .

[0111] In step (17), the thickness of the GaAs cap layer is 0.1 μm, the doping source is DEZn, and the doping concentration is 4×10 19 atoms / cm 3 .

[0112] Other steps and conditions are consistent with those in Example 1.

[0113] Example 3

[0114] A method for preparing an AlGaInP red semiconductor laser with a V-type mode extension layer is as described in Example 1, except that:

[0115] In step (2), the thickness of the GaAs buffer layer is 0.3 μm, and the doping concentration of silicon atoms is 5×10 18 atoms / cm 3 .

[0116] In step (4), Ga 0.5 In 0.5 The thickness of the P lower transition layer is 0.3 μm and the doping concentration is 5×10 18 atoms / cm 3 .

[0117] In step (5), Al 0.5 In 0.5 The thickness of the first lower confinement layer is 1 μm and the doping concentration is 2×10 18 atoms / cm 3 .

[0118] In step (6), the composition of the V-type change (Al a1 Ga 1-a1 ) b1 In 1-b1 The thickness of the P-mode extension layer is 0.03 μm and the doping concentration is 2×10 18 atoms / cm 3 , where a1 in the 0.015 μm thickness mode extension layer gradually changes from 0.95 to 0.8, and in the other 0.015 μm thickness mode extension layer, a1 gradually changes back from 0.8 to 0.95, and b1 = 0.6.

[0119] In step (7), Al 0.5 In 0.5 The thickness of the second lower confinement layer is 0.2 μm and the doping concentration is 2×10 18 atoms / cm 3 . .

[0120] In step (8), (Al x1 Ga 1-x1 ) y1 In 1-y1 The thickness of the waveguide layer under P is 0.15 μm, it is not intentionally doped, x1 gradually changes from 0.95 to 0.6, and y1 = 0.6.

[0121] In step (9), Ga 1-x2 In x2 The thickness of the P first quantum well is 7 nm, it is not intentionally doped, and x2=0.5.

[0122] In step (10), (Al x3 Ga 1-x3 ) y2 In 1-y2 The thickness of the P barrier layer is 15 nm, it is not intentionally doped, x3=0.7, y2=0.6.

[0123] In step (11), Ga 1-x4 In x4The thickness of the P second quantum well is 7 nm, it is not intentionally doped, and x4=0.5.

[0124] In step (12), (Al x5 Ga 1-x5 ) y3 In 1-y3 The thickness of the waveguide layer on P is 0.15 μm, of which 0.075 μm away from the quantum well is doped with zinc atoms. The doping source is DEZn, and the doping concentration is 7×10 17 atoms / cm 3 .

[0125] In step (13), Al 0.5 In 0.5 The thickness of the first upper confinement layer of P is 0.3 μm, the doping source is DEZn, and the doping concentration is 1.5×10 18 atoms / cm 3 .

[0126] In step (14), Ga 1-x6 In x6 The thickness of the P corrosion stop layer is 20 nm, the doping source is DEZn, and the doping concentration is 3×10 18 atoms / cm 3 , x6=0.5.

[0127] In step (15), Al 0.5 In 0.5 The thickness of the second upper confinement layer is 1.2 μm, the doping source is DEZn, and the doping concentration is 1.5×10 18 atoms / cm 3 .

[0128] In step (16), Ga 0.5 In 0.5 The thickness of the transition layer on P is 40 nm, the doping source is DEZn, and the doping concentration is 3×10 18 atoms / cm 3 .

[0129] In step (17), the thickness of the GaAs cap layer is 0.5 μm, the doping source is DEZn, and the doping concentration is 1×10 20 atoms / cm 3 .

[0130] Other steps and conditions are consistent with those in Example 1.

[0131] Example 4

[0132] A method for preparing an AlGaInP red semiconductor laser with a V-type mode extension layer is as described in Example 1, except that:

[0133] In step (5), the reaction temperature is 710°C.

[0134] In step (6), the reaction temperature is 710°C.

[0135] In step (7), the reaction temperature is 710°C.

[0136] In step (8), the reaction temperature is 640°C.

[0137] In step (9), the reaction temperature is 640°C.

[0138] In step (10), the reaction temperature is 640°C.

[0139] In step (11), the reaction temperature is 640°C.

[0140] In step (12), the reaction temperature is 710°C.

[0141] In step (13), the reaction temperature is 710°C.

[0142] In step (14), the reaction temperature is 710°C.

[0143] In step (15), the reaction temperature is 710°C.

[0144] In step (16), the reaction temperature is 670°C.

[0145] In step (17), the reaction temperature is 530°C.

[0146] Other steps and conditions are consistent with those in Example 1.

[0147] Test example

[0148] The conventional AlGaInP red semiconductor laser and the laser described in Example 1 of the present invention were first coated with a 300 μm cavity length and 5 μm strip width, and then photoluminescence (PL) tests were performed. The results are as follows: Figure 3 shown.

[0149] Depend on Figure 3 From the comparison results, it can be seen that compared with the conventional AlGaInP red light semiconductor laser, the threshold currents of the laser described in Example 1 of the present invention are 10.2 mA and 10.3 mA, respectively, and the output powers at 40 mA are 28.2 mW and 26.6 mW, respectively. It can be seen that when the laser described in Example 1 of the present invention is inserted into the V-shaped component gradient mode extension layer, the threshold current does not change significantly, and the output power increases at the same current. The reason may be that the offset of the light field to the P side is eliminated, thereby reducing the carrier absorption on the P side.

Claims

1. An AlGaInP red light semiconductor laser with a V-type mode extension layer, characterized in that: From bottom to top, it includes GaAs substrate, GaAs buffer layer, Ga 0.5 In 0.5 P lower transition layer, Al 0.5 In 0.5 P first lower limiting layer, V-type composition change (Al a1 Ga 1-a1 ) b1 In 1-b1 P-mode extension layer, Al 0.5 In 0.5 P second lower confinement layer, (Al x1 Ga 1-x1 ) y1 In 1-y1 P lower waveguide layer, Ga 1-x2 In x2 P first quantum well, (Al x3 Ga 1-x3 ) y2 In 1-y2 P barrier layer, Ga 1-x4 In x4 P second quantum well, (Al x5 Ga 1-x5 ) y3 In 1-y3 P upper waveguide layer, Al 0.5 In 0.5 P first upper confinement layer, Ga 1-x6 In x6 P corrosion stop layer, Al 0.5 In 0.5 P second upper confinement layer, Ga 0.5 In 0.5 P upper transition layer and GaAs cap layer; Among them, 0.55≤a1≤0.95, 0.4≤b1≤0.6; the a1 component changes from large to small and then from small to large, showing a V-shaped change.

2. The AlGaInP red light semiconductor laser with a V-type mode extension layer according to claim 1, wherein: Include one or more of the following conditions: i. The substrate is a GaAs substrate; ii. The GaAs buffer layer is made of GaAs material doped with silicon atoms, with a doping source of Si2H6, a thickness of 0.1-0.3 μm, and a doping concentration of 2×10 18 -5×10 18 atoms / cm 3 ; iii. the Ga 0.5 In 0.5 The P lower transition layer is doped with silicon atoms, the doping source is Si2H6, the thickness is 0.1-0.3μm, and the doping concentration is 2×10 18 -5×10 18 atoms / cm 3 ; iv. the Al 0.5 In 0.5 The first lower confinement layer is n-type Al 0.5 In 0.5 The first lower limiting layer P is doped with silicon atoms, the doping source is Si2H6, the thickness is 0.5-1μm, and the doping concentration is 7×10 17 -2×10 18 atoms / cm 3 ; v, the composition V type change (Al a1 Ga 1-a1 ) b1 In 1-b1 The P-mode extension layer is doped with silicon atoms, the doping source is Si2H6, the thickness is 0.01-0.03μm, and the doping concentration is 7×10 17 -2×10 18 atoms / cm 3 , where a1 changes gradually from 0.95 to 0.55 in the mode expansion layer of half thickness, and changes gradually back to 0.95 from 0.55 in the mode expansion layer of the other half thickness, 0.4≤b1≤0.6; vi. the A1 0.5 In 0.5 The second lower confinement layer of P is n-type Al 0.5 In 0.5 The second lower limiting layer of P is doped with silicon atoms. The doping source is Si2H6, the thickness is 0.05-0.2μm, and the doping concentration is 7×10 17 -2×10 18 atoms / cm 3 .

3. The AlGaInP red light semiconductor laser with a V-type mode extension layer according to claim 2, characterized in that: Include one or more of the following conditions: i. The thickness of the buffer layer is 0.2 μm and the doping concentration of silicon atoms is 2×10 18 atoms / cm 3 ; ii. The Ga 0.5 In 0.5 The thickness of the P lower transition layer is 0.2 μm; the doping concentration is 4×10 18 atoms / cm 3 ; iii. the Al 0.5 In 0.5 The thickness of the first lower confinement layer is 0.9 μm; the doping concentration is 1×10 18 atoms / cm 3 ; iv. V-type change of the component (Al a1 Ga 1-a1 ) b1 In 1-b1 The thickness of the P-mode extension layer is 0.02 μm and the doping concentration is 1×10 18 atoms / cm 3 , where a1 in the 0.01 μm thickness mode extension layer gradually changes from 0.95 to 0.7, and in the other 0.01 μm thickness mode extension layer, a1 gradually changes from 0.7 back to 0.95, and b1 = 0.5; v. the Al 0.5 In 0.5 The thickness of the second lower confinement layer is 0.1 μm; the doping concentration is 1×10 18 atoms / cm 3 .

4. The AlGaInP red light semiconductor laser with a V-type mode extension layer according to claim 1, wherein: Include one or more of the following conditions: i. x1 Ga 1-x1 ) y1 In 1-y1 The thickness of the waveguide layer under P is 0.05-0.15 μm, not intentionally doped, 0.45≤x1≤0.95, 0.4≤y1≤0.6; ii. The Ga 1-x2 In x2 The thickness of the P first quantum well is 4-7 nm, unintentionally doped, 0.3≤x2≤0.5, and compressively strained; iii. (Al x3 Ga 1-x3 ) y2 In 1-y2 The thickness of the P barrier layer is 5-15nm, not intentionally doped, 0.4≤x3≤0.7, 0.4≤y2≤0.6, and is under tensile strain; iv. the Ga 1-x4 In x4 The thickness of the P second quantum well is 4-7nm, unintentionally doped, 0.3≤x4≤0.5, and is compressively strained; v. the (Al x5 Ga 1-x5 ) y3 In 1-y3 The waveguide layer on P is doped with magnesium atoms or zinc atoms. The doping source is Cp2Mg or DEZn. The doping form is half doping. The thickness is 0.05-0.15μm and the doping concentration is 3×10 17 -7×10 17 atoms / cm 3 , x5 gradually changes from 0.5 to 0.95, 0.4≤y3≤0.

6.

5. The AlGaInP red light semiconductor laser with a V-type mode extension layer according to claim 4, characterized in that: Include one or more of the following conditions: i. x1 Ga 1-x1 ) y1 In 1-y1 The thickness of the waveguide layer under P is 0.1 μm, x1 gradually changes from 0.95 to 0.5, and y1 = 0.5; ii. The Ga 1-x2 In x2 The thickness of the first quantum well P is 5 nm, x2 = 0.4; iii. (Al x3 Ga 1-x3 ) y2 In 1-y2 The thickness of the P barrier layer is 6 nm, x3 = 0.65, y2 = 0.42; iv. the Ga 1-x4 In x4 The thickness of the second quantum well P is 5 nm, x4 = 0.4; v. the (Al x5 Ga 1-x5 ) y3 In 1-y3 The thickness of the P upper waveguide layer is 0.1 μm, and the 0.05 μm upper waveguide layer away from the quantum well is doped with magnesium atoms. The doping source is Cp2Mg, and the doping concentration is 4×10 17 atoms / cm 3 , x5 gradually changes from 0.5 to 0.95, y3=0.

5.

6. The AlGaInP red light semiconductor laser with a V-type mode extension layer according to claim 1, wherein: Include one or more of the following conditions: i. the Al 0.5 In 0.5 The first upper confinement layer is p-type Al 0.5 In 0.5 The first upper confinement layer P is doped with magnesium atoms or zinc atoms, the doping source is Cp2Mg or DEZn, the thickness is 0.1-0.3μm, and the doping concentration is 7×10 17 -1.5×10 18 atoms / cm 3 ; ii. The Ga 1-x6 In x6 The P corrosion stop layer is doped with magnesium atoms or zinc atoms. The doping source is Cp2Mg or DEZn. The thickness is 8-20nm and the doping concentration is 1.2×10 18 -3×10 18 atoms / cm 3 , 0.4≤x6≤0.5; iii. the Al 0.5 In 0.5 The second upper confinement layer is p-type Al 0.5 In 0.5 The second upper confinement layer is doped with magnesium atoms or zinc atoms. The doping source is Cp2Mg or DEZn. The thickness is 0.5-1.2μm and the doping concentration is 7×10 17 -1.5×10 18 atoms / cm 3 ; iv. the Ga 0.5 In 0.5 The transition layer on P is doped with magnesium atoms or zinc atoms. The doping source is Cp2Mg or DEZn. The thickness is 20-40nm and the doping concentration is 1.2×10 18 -3×10 18 atoms / cm 3 ; v. The GaAs cap layer is made of GaAs material doped with carbon atoms, the doping source is CBr4 or DEZn, the thickness is 0.1-0.5 μm, and the doping concentration is 4×10 19 -1×10 20 atoms / cm 3 .

7. The AlGaInP red light semiconductor laser with a V-type mode extension layer according to claim 6, characterized in that: Include one or more of the following conditions: i. the Al 0.5 In 0.5 The thickness of the first upper confinement layer of P is 0.15 μm, the doping source is Cp2Mg, and the doping concentration is 1×10 18 atoms / cm 3 ; ii. The Ga 1-x6 In x6 The thickness of the P corrosion stop layer is 10 nm, the doping source is Cp2Mg, and the doping concentration is 1.5×10 18 atoms / cm 3 , x6=0.47; iii. the Al 0.5 In 0.5 The thickness of the second upper confinement layer of P is 0.7 μm, the doping source is Cp2Mg, and the doping concentration is 1×10 18 atoms / cm 3 ; iv. the Ga 0.5 In 0.5 The thickness of the transition layer on P is 24 nm, the doping source is Cp2Mg, and the doping concentration is 2×10 18 atoms / cm 3 ; v. The thickness of the GaAs cap layer is 0.2 μm, the doping source is CBr4, and the doping concentration is 7×10 19 atoms / cm 3 .

8. A method for preparing an AlGaInP red semiconductor laser with a V-type mode extension layer according to any one of claims 1 to 7, comprising the following steps: The substrate is subjected to surface heat treatment in the MOCVD growth chamber, and then the GaAs substrate, GaAs buffer layer, GaAs and GaAs are grown epitaxially from bottom to top. 0.5 In 0.5 P lower transition layer, Al 0.5 In 0.5 P first lower limiting layer, V-type composition change (Al a1 Ga 1-a1 ) b1 In 1-b1 P-mode extension layer, Al 0.5 In 0.5 P second lower confinement layer, (Al x1 Ga 1-x1 ) y1 In 1-y1 P lower waveguide layer, Ga 1-x2 In x2 P first quantum well, (Al x3 Ga 1-x3 ) y2 In 1-y2 P barrier layer, Ga 1-x4 In x4 P second quantum well, (Al x5 Ga 1-x5 ) y3 In 1-y3 P upper waveguide layer, Al 0.5 In 0.5 P first upper confinement layer, Ga 1-x6 In x6 P corrosion stop layer, Al 0.5 In 0.5 P second upper confinement layer, Ga 0.5 In 0.5 P upper transition layer and GaAs cap layer.

9. The preparation method according to claim 8, wherein The steps are as follows: (1) placing a GaAs substrate in a growth chamber of an MOCVD device, heating the substrate to 710-730° C. in an H2 environment and baking the substrate for 20-40 minutes, then introducing AsH3 and baking the substrate for 20-40 minutes to obtain a heat-treated GaAs substrate; performing a high-temperature heat treatment on the GaAs substrate to remove water and oxygen from the substrate surface, and preparing for step (2); (2) Lowering the temperature to 670-690°C at a cooling rate of no more than 30°C / min, introducing TMGa and AsH3, and growing a GaAs buffer layer on the GaAs substrate; the purpose is to prevent defects from propagating from the substrate into the confinement layer, provide a fresh growth interface, and improve the quality of material growth; (3) Maintaining the temperature at 670-690°C, introducing TMGa, PH3 and AsH3, and stopping the introduction of AsH3 and TMGa during the growth process on the GaAs buffer layer to achieve a growth pause. The pause time is 3s to 30s, and the As atoms in the reaction chamber are depleted; (4) Maintaining the temperature at 670-690°C, continue to introduce TMGa, TMIn and PH3 to grow GaAs on the GaAs buffer layer. 0.5 In 0.5 P lower transition layer; The purpose is to reduce the band gap mutation and increase the electron migration rate; (5) Raise the temperature to 690-710℃ at a rate not higher than 60℃ / min, introduce TMAl, TMIn and PH3, and 0.5 In 0.5 Al growth on the transition layer below P 0.5 In 0.5 P first lower limiting layer; (6) Maintain the temperature at 690-710℃, introduce TMAl, TMGa, TMIn and PH3, and 0.5 In 0.5 The growth composition of the first lower confinement layer is V-shaped (Al a1 Ga 1-a1 ) b1 In 1-b1 In the P-mode extension layer, by changing the flow rates of TMAl and TMGa while keeping the flow rate of TMIn constant, a V-shaped change of the Al composition from large to small and then from small to large is achieved; (7) Maintain the temperature at 690-710℃, continue to introduce TMAl, TMIn and PH3, and in the V-type change of the composition (Al a1 Ga 1-a1 ) b1 In 1-b1 Al growth on the P-mode extension layer 0.5 In 0.5 P second lower limiting layer; (8) Lower the temperature to 640-660℃, continue to introduce TMAl, TMIn, TMGa and PH3, 0.5 In 0.5 P second lower confinement layer grows (Al x1 Ga 1-x1 ) y1 In 1-y1 The waveguide layer under P; by changing the flow rate of TMAl and TMGa, while keeping the flow rate of TMIn unchanged, the Al composition is gradually changed. The gradual change of the band gap helps to improve the carrier injection efficiency and enhance the photoelectric conversion efficiency; (9) Maintain the temperature at 640-660℃, continue to introduce TMIn, TMGa and PH3, and x1 Ga 1-x1 ) y1 In 1-y1 Ga is grown on the waveguide layer below P 1-x2 In x2 P first quantum well; (10) Keep the temperature at 640-660℃, continue to introduce TMAl, TMIn, TMGa and PH3, and 1-x2 In x2 P first quantum well (Al x3 Ga 1-x3 ) y2 In 1-y2 P barrier layer; (11) Maintain the temperature at 640-660℃, continue to introduce TMIn, TMGa and PH3, x3 Ga 1-x3 ) y2 In 1-y2 Ga growth on the P barrier layer 1-x4 In x4 P second quantum well; (12) Raise the temperature to 690-710℃, continue to introduce TMAl, TMIn, TMGa and PH3, and 1-x4 In x4 P second quantum well (Al x5 Ga 1-x5 ) y3 In 1-y3 The waveguide layer on the P top layer; by changing the flow rate of TMAl and TMGa, while keeping the flow rate of TMIn unchanged, the Al composition is gradually changed. The gradual change of the band gap helps to improve the carrier injection efficiency and enhance the photoelectric conversion efficiency; (13) Maintain the temperature at 690-710℃, continue to introduce TMAl, TMIn and PH3, x5 Ga 1-x5 ) y3 In 1-y3 P-type Al is grown on the P upper waveguide layer 0.5 In 0.5 P first upper confinement layer; (14) Maintain the temperature at 690-710℃, continue to introduce TMGa, TMIn and PH3, and 0.5 In 0.5 P-type GaN is grown on the first upper confinement layer. 1-x6 In x6 P corrosion stop layer; (15) Maintain the temperature at 690-710℃, continue to introduce TMAl, TMIn and PH3, and 1-x6 In x6 Al growth on P etch stop layer 0.5 In 0.5 P second upper confinement layer; (16) Lower the temperature to 670-690℃, introduce TMIn, TMGa and PH3, and 0.5 In 0.5 Ga is grown on the second upper confinement layer of P 0.5 In 0.5 P upper transition layer; (17) The temperature was lowered to 530-550 ° C, and the cooling rate did not exceed 40 ° C / min, and TMGa and AsH3 were continued to be introduced. 0.5 In 0.5 A GaAs cap layer is grown on the P upper transition layer.

10. The preparation method according to claim 9, wherein Include one or more of the following conditions: i. In step (1), the temperature was raised to 720°C in a H2 environment and baked for 30 minutes, and then AsH3 was introduced and baked for 30 minutes; ii. In step (2), the reaction temperature is 680°C; iii. In step (3), the reaction temperature is 680°C; iv. In step (4), the reaction temperature is 680° C.; v. In step (5), the reaction temperature is 700°C; vi. In step (6), the reaction temperature is 700° C.; vii. In step (7), the reaction temperature is 700° C.; viii. In step (8), the reaction temperature is 650° C.; ix. In step (9), the reaction temperature is 650° C.; x. In step (10), the reaction temperature is 650°C; xi. In step (11), the reaction temperature is 650°C; xii. In step (12), the reaction temperature is 700° C.; xiii. In step (13), the reaction temperature is 700° C.; xiv. In step (14), the reaction temperature is 700° C.; xv. In step (15), the reaction temperature is 700° C.; xvi. In step (16), the reaction temperature is 680°C; xvii. In step (17), the reaction temperature is 540°C.

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